Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previo...Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previous research,providing a long-term perspective on carbonyl compound variations and their environmental implica-tions.Atmospheric observations were conducted at Beijing(BJ)and Xianghe(XH)during the summer and winter months of 2018,2019,and 2023 to study the sources and impacts of carbonyl compounds in typical urban areas and peri‑urban areas.Notably,concentrations in the summer of 2023 increased compared to 2018 and 2019.The predominant carbonyl compounds—formaldehyde,acetaldehyde,and acetone—accounted for over 60%of the total.The mean values of OFP in BJ ranged from 18.55 to 58.61μg/m3,lower than those in XH(29.82 to 65.48μg/m3),with formaldehyde and acetaldehyde contributing over 80%of the total.SOAP exhibited a similar pattern,with values in XH(69.21 to 508.55μg/m3)significantly exceeding those in BJ(34.47 to 159.78μg/m3).The PMF model highlighted vehicle exhaust,secondary pollution,and biomass combustion as major sources of carbonyl compounds,emphasizing differences in source contributions between the two regions.This study’s com-parative analysis over different years and locations provides new insights into the dynamic changes in carbonyl compounds and their environmental importance.These results not only reinforce the importance of carbonyl compounds regulation but also offer a valuable reference for evaluating and refining emission control strategies during this period.展开更多
Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of...Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of catalytical materials.In 2019,we discussed the development trend of this field,and wrote a roadmap on this topic in Chinese Chemical Letters(30(2019)2065-2088).Nowadays,we discuss it again from a new viewpoint along this road.In this paper,several subtopics are discussed,e.g.,photocatalysis based on titanium dioxide,violet phosphorus,graphitic carbon and covalent organic frameworks,electrocatalysts based on carbon,metal-and covalent-organic framework.Finally,we hope that this roadmap can enrich the development of two-dimensional materials in environmental catalysis with novel understanding,and give useful inspiration to explore new catalysts for practical applications.展开更多
Interfacial conjugation was employed to engineering preparation of TiO2@NH2-MIL-101(Fe)heterojunction photocataysts through carboxylate bidentate linkage with TiO2 and NH2-MIL-101(Fe),which can enhance the electron tr...Interfacial conjugation was employed to engineering preparation of TiO2@NH2-MIL-101(Fe)heterojunction photocataysts through carboxylate bidentate linkage with TiO2 and NH2-MIL-101(Fe),which can enhance the electron transfer capability from metal-organic frameworks(MOFs)to TiO2 and photocatalytic activity.The carbon nanospheres derived from glucose act as reducing agent and template to synthesize oxygen vacancies TiO2 hollow nanospheres.Then,the oxygen vacancies were employed as antennas to connect 2-aminoterephtalic acid as bidentate carboxylate chelating linkage on TiO2,which have been proved by the density functional theory(DFT)calculations.Subsequently,NH2-MIL-101(Fe)was coordinatingly formed on the surface of TiO2.The conjugation effects between TiO2 and NH2-MIL-101(Fe)enhanced the electron transfer capability and could also induce the band tail states to narrow bandgap of the composites.Thus,the photodegradability of methylene blue was remarkably enhanced under visible light irradiation.The degradation rate of TiO2@17%NH2-MIL-101(Fe)was 0.131 min-1,which was about 3.5 and 65 times higher than that of NH2-MIL-101(Fe)and TiO2,respectively.展开更多
Precise calculation of the trajectory of store separation is critical in assess-ing whether the store can be released safely.Store ejection is the initial stage of the releasing process and any uncertainty introduced ...Precise calculation of the trajectory of store separation is critical in assess-ing whether the store can be released safely.Store ejection is the initial stage of the releasing process and any uncertainty introduced at this stage will propagate through the whole trajectory.In this work,the impact of the uncertainties in ejector modeling on the simulation of a generic store separation is investigated by using a Monte-Carlo-based approach.To reduce the extremely large computation cost resulted from the direct use CFD in Monte Carlo simulation,the CFD solutions are represented by a time-dependent Kriging model,which is constructed at each time step by using the samples from the URANS simulations.The stochastic outputs,including the distri-bution of probability density function,expected value and 95%confidence interval of store separation trajectory,are obtained by the Monte Carlo simulations.The sensitiv-ity analysis is also carried out by using the Monte-Carlo-based method to determine the most significant variables in ejector modeling,which affect the output uncertainty.Our results show that ejector modeling is one of the main uncertainty sources of store separation simulation and the approximation in ejector modeling can cause a signifi-cant deviation,especially in the angular displacement.展开更多
Traumatic brain injury(TBI)is intricately linked to the most severe clinical manifestations of brain damage.It encompasses dynamic pathological mechanisms,including hemodynamic disorders,excitotoxic injury,oxidative s...Traumatic brain injury(TBI)is intricately linked to the most severe clinical manifestations of brain damage.It encompasses dynamic pathological mechanisms,including hemodynamic disorders,excitotoxic injury,oxidative stress,mitochondrial dysfunction,inflammation,and neuronal death.This review provides a comprehensive analysis and summary of biomaterial-based tissue engineering scaffolds and nano-drug delivery systems.As an example of functionalized biomaterials,nano-drug delivery systems alter the pharmacokinetic properties of drugs.They provide multiple targeting strategies relying on factors such as morphology and scale,magnetic fields,pH,photosensitivity,and enzymes to facilitate the transport of therapeutics across the blood–brain barrier and to promote selective accumulation at the injury site.Furthermore,therapeutic agents can be incorporated into bioscaffolds to interact with the biochemical and biophysical environment of the brain.Bioscaffolds can mimic the extracellular matrix environment,regulate cellular interactions,and increase the effectiveness of local treatments following surgical interventions.Additionally,stem cell-based and exosome-dominated extracellular vesicle carriers exhibit high bioreactivity and low immunogenicity and can be used to design therapeutic agents with high bioactivity.This review also examines the utilization of endogenous bioactive materials in the treatment of TBI.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41905108 and 42130704).
文摘Carbonyl compounds play a pivotal role in the formation of secondary pollutants such as O_(3) and SOA,signifi-cantly impacting air quality and human health.This study extended the observation period compared to previous research,providing a long-term perspective on carbonyl compound variations and their environmental implica-tions.Atmospheric observations were conducted at Beijing(BJ)and Xianghe(XH)during the summer and winter months of 2018,2019,and 2023 to study the sources and impacts of carbonyl compounds in typical urban areas and peri‑urban areas.Notably,concentrations in the summer of 2023 increased compared to 2018 and 2019.The predominant carbonyl compounds—formaldehyde,acetaldehyde,and acetone—accounted for over 60%of the total.The mean values of OFP in BJ ranged from 18.55 to 58.61μg/m3,lower than those in XH(29.82 to 65.48μg/m3),with formaldehyde and acetaldehyde contributing over 80%of the total.SOAP exhibited a similar pattern,with values in XH(69.21 to 508.55μg/m3)significantly exceeding those in BJ(34.47 to 159.78μg/m3).The PMF model highlighted vehicle exhaust,secondary pollution,and biomass combustion as major sources of carbonyl compounds,emphasizing differences in source contributions between the two regions.This study’s com-parative analysis over different years and locations provides new insights into the dynamic changes in carbonyl compounds and their environmental importance.These results not only reinforce the importance of carbonyl compounds regulation but also offer a valuable reference for evaluating and refining emission control strategies during this period.
基金supported by the National Natural Science Foundation of China(Nos.52272290,21972030,52073119,and 52373210)the Natural Science Foundation of Jilin Province(No.20230101029JC)+1 种基金the Fundamental Research Program of Shanxi Province(No.202303021212159)the Monash University Malaysia–ASEAN grant(No.ASE-000010)。
文摘Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of catalytical materials.In 2019,we discussed the development trend of this field,and wrote a roadmap on this topic in Chinese Chemical Letters(30(2019)2065-2088).Nowadays,we discuss it again from a new viewpoint along this road.In this paper,several subtopics are discussed,e.g.,photocatalysis based on titanium dioxide,violet phosphorus,graphitic carbon and covalent organic frameworks,electrocatalysts based on carbon,metal-and covalent-organic framework.Finally,we hope that this roadmap can enrich the development of two-dimensional materials in environmental catalysis with novel understanding,and give useful inspiration to explore new catalysts for practical applications.
基金supported by the National Natural Science Foundation of China(51572022 and 51872025)the National Key Research and Development Program of China(2016 YFB0701100)the National Key Research and Development H863 Program of China(18H86303ZT0032702)。
文摘Interfacial conjugation was employed to engineering preparation of TiO2@NH2-MIL-101(Fe)heterojunction photocataysts through carboxylate bidentate linkage with TiO2 and NH2-MIL-101(Fe),which can enhance the electron transfer capability from metal-organic frameworks(MOFs)to TiO2 and photocatalytic activity.The carbon nanospheres derived from glucose act as reducing agent and template to synthesize oxygen vacancies TiO2 hollow nanospheres.Then,the oxygen vacancies were employed as antennas to connect 2-aminoterephtalic acid as bidentate carboxylate chelating linkage on TiO2,which have been proved by the density functional theory(DFT)calculations.Subsequently,NH2-MIL-101(Fe)was coordinatingly formed on the surface of TiO2.The conjugation effects between TiO2 and NH2-MIL-101(Fe)enhanced the electron transfer capability and could also induce the band tail states to narrow bandgap of the composites.Thus,the photodegradability of methylene blue was remarkably enhanced under visible light irradiation.The degradation rate of TiO2@17%NH2-MIL-101(Fe)was 0.131 min-1,which was about 3.5 and 65 times higher than that of NH2-MIL-101(Fe)and TiO2,respectively.
基金The work was financially supported by National Numerical Windtunnel(Grant No.NNW2019ZT7-B31)This research was also supported in part by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Precise calculation of the trajectory of store separation is critical in assess-ing whether the store can be released safely.Store ejection is the initial stage of the releasing process and any uncertainty introduced at this stage will propagate through the whole trajectory.In this work,the impact of the uncertainties in ejector modeling on the simulation of a generic store separation is investigated by using a Monte-Carlo-based approach.To reduce the extremely large computation cost resulted from the direct use CFD in Monte Carlo simulation,the CFD solutions are represented by a time-dependent Kriging model,which is constructed at each time step by using the samples from the URANS simulations.The stochastic outputs,including the distri-bution of probability density function,expected value and 95%confidence interval of store separation trajectory,are obtained by the Monte Carlo simulations.The sensitiv-ity analysis is also carried out by using the Monte-Carlo-based method to determine the most significant variables in ejector modeling,which affect the output uncertainty.Our results show that ejector modeling is one of the main uncertainty sources of store separation simulation and the approximation in ejector modeling can cause a signifi-cant deviation,especially in the angular displacement.
基金support from the National Natural Science Foundation of China(82273487)Young Medical Scientists Training Program(21QNPY051,China)the Shanghai Integration Achievement Program(2022-RH17,China).
文摘Traumatic brain injury(TBI)is intricately linked to the most severe clinical manifestations of brain damage.It encompasses dynamic pathological mechanisms,including hemodynamic disorders,excitotoxic injury,oxidative stress,mitochondrial dysfunction,inflammation,and neuronal death.This review provides a comprehensive analysis and summary of biomaterial-based tissue engineering scaffolds and nano-drug delivery systems.As an example of functionalized biomaterials,nano-drug delivery systems alter the pharmacokinetic properties of drugs.They provide multiple targeting strategies relying on factors such as morphology and scale,magnetic fields,pH,photosensitivity,and enzymes to facilitate the transport of therapeutics across the blood–brain barrier and to promote selective accumulation at the injury site.Furthermore,therapeutic agents can be incorporated into bioscaffolds to interact with the biochemical and biophysical environment of the brain.Bioscaffolds can mimic the extracellular matrix environment,regulate cellular interactions,and increase the effectiveness of local treatments following surgical interventions.Additionally,stem cell-based and exosome-dominated extracellular vesicle carriers exhibit high bioreactivity and low immunogenicity and can be used to design therapeutic agents with high bioactivity.This review also examines the utilization of endogenous bioactive materials in the treatment of TBI.
